according to the governor of connecticut, the rampage ended ten minutes after it began when the gunman heard wailing sirens approaching while he was in the second classroom, and she shot himself once in the head. >> we surmise it was during the second classroom episode he heard responders coming and apparently, that, had decided to take his own life. >> reporter: new clues about the 20-year-old shooter. computers and videos were removed from the lanza family home this weekend that could provide clues into his motive. friends of adam's murdered mother, nancy, say she was increasingly concerned about her son's behavioral issues over the last few months. >> i think it was just getting difficult for her to try to get him into regular life. >> reporter: all of the schools in the area are closed today. students from sandy hook elementary school will resume classes at a neighboring school in a matter of days. rob and sunny? >> in a tragedy like this, it's so important to try to remember the victims, perhaps, more than the gunman here. but we have learned some more about adam lanza, correct? >